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The construction of the sixth antenna is progressing well, but the
antenna should become operational by the end of the year, at the
earliest. Investigators are therefore asked to submit proposals on
the availability of five antennas only. Projects will be properly
adjusted in observing time and uv-coverage as soon as the sixth
antenna should become available.
As last winter, we will still rely on ground transport and transport
by helicopter. This will limit the number of people on the site and so
our ability to carry out configuration changes under typical winter
conditions. We therefore ask investigators to submit proposals for the
D, C2 and B1 configurations only. The D and C2 configurations have
already been offered last winter. These configurations provide already
a large number of possibilities: deep integrations (D), low (CD) and
medium to high (BC) resolution observations in the snapshot, mapping
or mosaicing modes. The BC set of configurations, for instance,
provides an angular resolution better than 1
at 230 GHz and
declination. The scheduling priority is expected to be on
the D configuration until December and towards end of the winter
session, more extended configurations (C2 and B1) are likely not to be
Applications should also take into account the capabilities of the new
six antenna correlator. Please note that the instrumental bandwidth
will be limited by the receivers, i.e. the extended bandwidth of the
correlator will not yet be fully available on the sky.
Observing proposals are invited for the Plateau de Bure Interferometer
for the period Nov 15, 2001 to May 15, 2002. The deadline for applications is September 5th, 2001 16:00h (MET).
Under normal operating conditions, IRAM schedules and completes
between 30 and 50 projects during the winter period, with an elapsed
time of at least two months between start and end of any given
project. Selection is based on scientific merit, technical
feasibility, and adequacy to the instrument.
Details of the PdBI and the observing procedures are given in the
document ``The Plateau de Bure Interferometer
(PdBI)''. A copy can be obtained from
the address below or from the World-Wide-Web at http://iram.fr/PDBI/bure.html). Proposers should read this document
carefully before submitting any proposal.
We strongly encourage the submission via the electronic submission
facility available at http://iram.fr/submission/submission.html. Note that applications
sent by e-mail will not be accepted. Applications sent by fax or
postal mail should be addressed to:
IRAM Scientific Secretariat
Interferometer Observing Proposal
300 Rue de la Piscine
F-38406 Saint Martin d'Hères Cédex
Proposal templates proposal.tex as well as the Latex style file
proposal.sty can be retrieved by anonymous ftp from iram.fr (in directory dist/proposal); or from the Internet via
http://iram.fr/proposal/proposal.html. In case of problems, contact
the scientific secretary, Mrs Cathy Berjaud
Do not use characters smaller than 11pt, which could make your
proposal illegible when duplicated or faxed. For the same reasons,
also avoid sending figures with grey scale maps by fax. In case your
proposal reaches us in time, but is incomplete or unreadable when
copied, we will try our best to contact you. The Principal
Investigator will receive by return mail an acknowledgement of receipt
and the proposal number.
The scientific aims of the proposed programme should be explained in 2
pages of text maximum, plus up to two pages of figures, tables,
and references. Proposals should be self-explanatory, clearly state
their aims, and explain the need of the Plateau de Bure
In all cases, indicate on the first page whether your proposal is (or
is not) the resubmission of a proposal or
the continuation of a previously accepted proposal. In the case of a
resubmission, state very briefly in the introduction why the proposal
is being resubmitted (e.g. improved scientific justification,
For this call for proposals, please note the following guidelines.
Proposals should be submitted for one of the five categories:
The proposal category will have to be specified on the proposal cover
sheet and should be carefully considered by proposers.
- Proposals that ask for 1.3mm data only.
3mm receivers will be used for pointing and calibration purposes, but cannot
provide any imaging.
- Proposals that ask for 3mm data only.
1.3 mm receivers can still be used to provide either phase stability
information or purely qualitative information such as the mere
existence of fringes.
- dual freq.:
- Proposals that ask for dual-frequency
observations (i.e. simultaneous observations at 3mm and 1.3mm).
- time filler:
- Proposals that have to be considered as
background projects to fill in periods where the atmospheric
conditions do not allow mapping, or eventually, to fill in gaps in the
scheduling, or even periods when only a subset of the standard
5-antenna configurations will be available. These proposals will be
carried out on a ``best effort'' basis only.
- Exploratory proposals: proposals whose
scientific interest justifies the attempt to use the PdB array beyond
its guaranteed capabilities. This category includes for example
non-standard frequencies for which the tuning cannot be guaranteed,
and more generally all non-standard observations. These proposals will
be carried out on a ``best effort'' basis only.
The configurations for the winter period will be:
Projects will be properly adjusted in observing time and uv-coverage
as soon as the sixth antenna becomes available. Investigators are
asked to indicate possible tradeoffs should the requested
configuration not be available.
|5 Antenna configurations
||W05 W00 E03 N05 N09
||W12 W09 E10 N05 N15
||W12 E18 E23 N13 N20
The following configuration sets are available:
||Detection, ``Low'' resolution mapping at 1.3 mm
resolution at 3mm, 1.8
resolution at 1.3 mm
resolution at 3 mm
Enter ANY in the proposal form if your project
doesn't need a particular configuration.
All antennas are equipped with fully operational dual frequency
receivers. The available frequency range will be 82 GHz to 116 GHz for
the 3mm band, and 205 to 245 GHz for the 1.3 mm band. The 3mm and
1.3mm receivers are aligned to within
Below 105 GHz, receivers offer best performances in LSB tuning
with high rejection (20 dB): expected system temperatures are
scale) 100 to 150 K for the winter time. Above 110 GHz,
best performances are obtained with USB tuning, low rejection
(4 to 6 dB): expected system temperatures are 250 K at 115 GHz.
The 1.3 mm receivers give DSB tuning with typical T
50 K. Expected SSB system temperature are 250 to 350 K. The
guaranteed tuning range is 205-245 GHz, but it may be possible to
reach lower frequencies for specific cases. Higher frequencies are not
feasible because of limitations in the triplers.
Software is available to provide real-time atmospheric phase
compensation on spectral and continuum data, as well as a-posteriori
processing for continuum data. Experience shows that a final phase
noise below 30
at 230 GHz may be obtained under good
The rms noise can be computed from
is the system temperature in Tr* scale (150 K below
110 GHz, 300 K at 115 GHz, 500 K at 230 GHz)
is the conversion factor from Kelvin to Jansky (22 at 3mm,
35 at 1.3mm)
is an efficiency factor due to atmospheric phase noise
(0.9 at 3 mm, 0.8 at 1.3 mm)
is the number of antennas (5), and
is the basic number
of configurations (1 for D, 2 for CD, 2 for BC)
- T is the integration time per configuration in seconds (3 to 8
hours, depending on source declination)
- B is the channel bandwidth in Hz (500 MHz for continuum, 40
kHz to 2.5 MHz for spectral line, according to spectral
Investigators have to specify the one sigma noise level which is
necessary to achieve each individual goal of a proposal, and in
particular for projects aiming at deep integrations.
The interferometer operates in the J2000.0 system. For best
positioning accuracy, source coordinates must be in the J2000.0 system;
position errors up to
may occur otherwise.
Please do not forget to specify LSR velocities for the sources. For
pure continuum projects, the ``special'' velocity NULL (no Doppler
tracking) can be used.
Coordinates and velocities in the proposal MUST BE CORRECT:
A coordinate error is a potential cause for proposal rejection.
The new correlator has 8 independent units, each being tunable
anywhere in the 110-680 MHz band, and providing 7 different modes of
configuration (characterized in the following by pairs of numbers
giving the total
bandwidth/number of channels). In the first 3 modes: 320MHz/128,
160MHz/256, 80MHz/512 the two central channels may be perturbed by the
Gibbs phenomenon (depending on continuum strength). When using these
modes, it is recommended to avoid centering the most important part of
the lines in the middle of the band of the correlator unit. In the
remaining modes: 160MHz/128, 80MHz/256, 40MHz/512 and 20MHz/512 the
two central channels are not affected by the Gibbs phenomenon and,
therefore, these modes should be preferred for spectroscopic
The 8 units can be independently placed either on the IF1
(3mm receiver) or on the IF2 (1.3mm receiver).
For safety reasons, the sun avoidance circle has been extended to 45
degrees. Please take this into account for your sources and the
The PdBI has mosaicing capabilities, but the pointing accuracy may be
a limiting factor at the highest frequencies. Please contact R. Neri
in case of doubts.
Proposers should be aware of constraints for data reduction:
Data reduction will be carried out on the dedicated HP workstations.
- In general, data should be reduced in Grenoble. Proposers
will not come for the observations, but will have to come for the
- We keep the data reduction schedule very flexible, but wish to
avoid the presence of more than 2 groups at the same time in
Grenoble. Please contact us in advance.
- In certain cases we give the possibility to eavesdrop on the
uv-tables obtained on a project shortly after the observations. Please
contact us if you are interested in this option.
- IRAM may consider splitting the data reduction in two phases:
intermediate calibration and final mapping. Such a splitting is often
necessary for the high resolution images. In such a case, the
proposers must be ready to come at IRAM for fast data reduction of the
- CLIC is still evolving to cope with the evolution of the
PdBI array. The newer versions are upward compatible with the previous
releases, but the reverse is not true. Observers wanting to finish
data reduction at their home institute should obtain an updated
version of CLIC, which is now available. Because differences between
CLIC versions may potentially result in imaging errors if new data is
reduced with an old package, we insist that observers using a copy of
CLIC take special care in maintaining it up-to-date.
A local contact will be assigned to every A or B - rated proposal
which does not
involve an in-house collaborator. Depending upon the programme
complexity, IRAM may require an in-house collaborator instead of the
normal local contact.
All proposals will be reviewed for technical feasibility in parallel
to being sent to the members of the programme committee. Please help
in this task by submitting technically precise proposals. Note that
your proposal must be complete and exact: velocities, position
and frequency setup must be exactly specified.
Please contact R.Neri or R.Lucas in case of doubt about the
feasibility of a non-standard program.
The documentation for the IRAM Plateau de Bure Interferometer includes
documents of general interest to potential users:
More specialized documents are also available; they are intended for
observers on the site (IRAM on-duty astronomers, operators, or observers
with non-standard programs):
Finally, we would like to stress again the importance of the quality
of the observing proposal. The technical preparation of observing
proposals is unfortunately often insufficient. In the past, proposals
were received which did not even include exact observing frequencies
or even source coordinates, or worse, revealing coordinates with the wrong
epoch !... The IRAM interferometer is a powerful, but complex
instrument, and proposal preparation requires special
care. Information is available in the documentation and at
http://iram.fr/PDBI/bure.html. The IRAM staff can help in case of
doubts if contacted well before the deadline. Note that the proposal
should not only justify the scientific interest, but also demonstrate
how the Plateau de Bure interferometer will bring new information.
Next: Scientific Results in Press
Up: IRAM Newsletter 49 (August 2001)